Superior Posterior Mediastinum

Question 1

Boundaries of Superior Mediastinum

• Anterior
• Posterior
• Inferior
• Superior

Answer 1

• Manubrium
• Bodies of T1-T4
• Transverse thoracic plane
• Thoracic inlet

Question 2

Contents of Superior Mediastinum

• Found in only the superior mediastinum
• Also found in other parts of the mediastinum

Answer 2

• Thymus, brachiocephalic veins, arch of aorta and trachea.
• SVC, oesophagus, phrenic and vagus nerves, and lymphatics.

Question 3

Branches from arch of aorta

• Right
• Left

Answer 3

• Brachiocephalic trunk which branches to become the right common carotid artery and the right subclavian artery
• Left common carotid artery and left subclavian artery immediately

Question 4

Vagus Nerves (X)

• Pass through diaphragm with…

Answer 4

• Oesophagus @ T10

Question 5

Phrenic Nerves (C3, C4, C5)

• Right phrenic nerve
• Left phrenic nerve

Answer 5

• Associated with the right brachiocephalic vein and the SVC. Also associated with the pericardium over the right atrium. Pierces diaphragm near the caval opening @ T8.
• Located more laterally. Across left subclavian artery and vein and then across the surface of the pericardium and through the diaphragm.

Question 6

Trachea

• Runs from
• Bifurcation
• C shaped rings joined by
• Directly posterior is…?

Answer 6

• Bottom of larynx @ C6/7 until the carina
• Occurs at the carina. Bifurcates @ T4/5 which is the transverse thoracic plane.
• C shaped rings of cartilage joined by the trachealis muscle
• Oesophagus

Question 7

Oesophagus

• What is it?
• Where does it run from and to?
• Constrictions

Answer 7

• Fibromuscular tube
• C6 to T10, with a brief abdominal course after passing through diaphragm before entering stomach.
• Arch of arorta, left bronchus and the diaphragm.

Question 8

Boundaries of Posterior Mediastinum

• Anterior
• Posterior
• Inferior
• Superior

Answer 8

• Parietal pleura
• Bodies of T5-T12 vertebra
• Pericardium and diaphragm
• Transverse thoracic plane

Question 9

Posterior intercostal veins on the:

• Right side
• Left side

Answer 9

• Go back in the azygos vein
• Go back via the accessory hemiazygos, brachiocephalic and hemiazygos veins.

Question 10

Thoracic Duct

• Empties

Answer 10

• At junction of left subclavian and left internal jugular veins.

Question 11

Sympathetic Chain

• Chain of sympathetic ganglia

Answer 11

• Extends length of vertebral column. Provides an outflow of sympathetic innervation between T1-L2/3

Question 12

Splanchnic Nerves

• Greater
• Lesser
• Least
• Supply

Answer 12

• T5-T9 ganglia. Go into coeliac and superior mesenteric ganglia.
• T10 + T11 ganglia. Become superior mesenteric and aorticorenal ganglia.
• T12 ganglion. Becomes aorticorenal ganglion.
• Sympathetic innervation to the abdominal viscera

Question 13

Diaphragm - What passes through at:

• T8
• T10
• T12

Answer 13

• IVC through the caval opening
• Oesophagus and vagal trunks through the oesophageal hiatus
• Aorta, thoracic duct and azygos vein through the aortic hiatus. Greater and lesser splanchnic nerves through openings in the crura. Least splanchnic nerve and sympathetic nerve go through behind the medial arcuate ligament.